There’s no digital output from the CRSS12s.
When you use them without needles, they still output a control tone through the phono RCAs. The tone is just generated internally. You can select between Rekordbox or Serato tones.
IIRC you can use Algoriddim DVS today with a Serato control vinyl. Therefore you will also be able to use the CRSS12 in non-needle mode with the Magvel clamp.
